From: Jeff King <peff@peff•net>
To: "Crabtree, Andrew" <andrew.crabtree@hp•com>
Cc: "git@vger•kernel.org" <git@vger•kernel.org>
Subject: Re: Plumbing version of 'git branch --contains' ?
Date: Thu, 23 Oct 2014 10:19:22 -0700 [thread overview]
Message-ID: <20141023171921.GA25061@peff.net> (raw)
In-Reply-To: <B82B660D4887C042850326C2BC65FE035D58B11E@G9W0757.americas.hpqcorp.net>
On Wed, Oct 22, 2014 at 08:19:07PM +0000, Crabtree, Andrew wrote:
> I need to get a list of refs that can reach a certain SHA in in a script.
>
> git branch --contains SHA
>
> would be great (runs in ~2 seconds), but not my preferred option for scripting.
>
> I tried
>
> for br in $(git for-each-ref --format='%(refname:short)' refs/heads/)
> do
> git merge-base --is-ancestor $1 ${br}
> if [ $? -eq 0 ]
> then
> echo "${br}"
> fi
> done
>
> Which gives me perfect output, but takes 82 seconds to run in my environment.
Right. There's some setup work that happens in `git branch --contains`
that we end up repeating.
> Is there an alternative I'm missing to give me the run time
> performance of 'git branch --contains' but with stable output suitable
> for parsing?
Sadly, no, there isn't currently. The right tool would be `git
for-each-ref --contains`, but it doesn't exist yet. I was working
towards it, but got stopped on factoring out a `--contains` traversal
suitable for both `git tag` and `git branch` (they currently are
different and make performance tradeoffs based on the expected depth of
the merge bases, which is usually different between tags and
branches)[1]. That's work I'd love to resume, but I haven't gotten
around to it yet.
-Peff
[1] http://thread.gmane.org/gmane.comp.version-control.git/252472
next prev parent reply other threads:[~2014-10-23 17:19 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-22 20:19 Plumbing version of 'git branch --contains' ? Crabtree, Andrew
2014-10-23 17:19 ` Jeff King [this message]
2014-10-23 18:07 ` Junio C Hamano
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